Conventionally, there have been proposed techniques (referred to as “score alignment”) for performing analysis on a position in a piece of music at which position a user is currently performing the piece of music. Non-Patent Documents 1 and 2, for example, each disclose a technique for analyzing temporal correspondence between positions in a piece of music and sound signals representing performance sounds of the piece of music, by use of a probability model, such as a hidden Markov model (HMM).